Prolation \Pro*la"tion\, n. [L. prolatio: cf. F. prolation.] 1. The act of prolating or pronouncing; utterance; pronunciation. [Obs.] --Ray. 2. The act of deferring; delay. [Obs.] --Ainsworth. 3. (Mus.) A medi[ae]val method of determining of the proportionate duration of semibreves and minims. --Busby.